1. Field of the Invention
The present invention relates to a process for preparing nitrogen-containing heterocyclic compounds. More particularly, the invention relates to a process for preparing nitrogen-containing heterocyclic compounds, such as triethylenediamines, piperidines and morpholines by dehydrocyclization or cracking cyclization (deammoniation) of compounds having formulas (I) and (II) in the presence of a zeolite catalyst containing a specific cation. ##EQU3## wherein X represents a hydrogen atom or --CH.sub.2 --CHR--Y group; R represents a hydrogen atom or methyl group; Y represents an --OH or --NH.sub.2 group and n represents the integers 0 or 1 to 4.
2. Description of the Prior Art
Triethylenediamines have been prepared by cyclization of the above compounds (I and II) in the presence of a metal phosphate catalyst (Japanese Pat. Publication No. 18589/1966) or a silica-alumina catalyst (Japanese Pat. Publication NO. 22597/1963; Japanese Pat. Publication No. 7707/1969).
A need exists, however, for a catalytic procedure for preparing a wide range of nitrogen heterocycles.